Are any of you familiar with the game MindTrap? To quote Wikipedia on the game: “The puzzles are logical, trick-type questions. Some are simply riddles to be thought out, and some give unnecessary information in order to distract the answerer from a simple, common sense solution, and play on common assumptions.”
So, my wife and I were sitting on our deck tonight enjoying the awesome weather we’ve been having in Georgia, while sipping some Gentleman Jack, and reading MindTrap questions to each other. We happened across this doozie:
It was a warm summers evening when Sid Shady and Sam Sham robbed the till at the ‘Soul-Ace Hotel’. Knowing the police were not far behind, they agreed it would be a ‘colder trail’ if they split the loot and parted company. Sid Shady took the high road far up into the mountains and Sam Slug headed for the coast. The first morning on the run, they each woke with a craving for hardboiled eggs. Since water boils at a lower temperature at higher altitudes, which of the two will get hardboiled eggs first?
Now ignoring the fact that Sam Sham and Sam Slug are presumably the same person, and a ‘colder trail’ doesn’t really make sense unless you talk about someone being ‘hot on their trail’; I was a little surprised by the answer. Maybe I just don’t understand physics.
Answer: Sam Slug (the guy that went to the coast). Water boils at 100 degrees Celcius at sea level, but the higher up you go the lower the boiling point. Therefore Shadyd’s eggs will be boiling at a lower temperature, and consequently take longer to cook.
My Take on it: I agree that water boils at a lower temperature the higher you go… but who cares? To me the only way the above answer would matter is if the water stopped getting hotter once it started boiling. That’s not what happens is it? Doesn’t water continue getting hotter until it eventually turns into steam? Or by definition, is water done getting hotter (or turn into steam) at the point it boils?
Actually, that is exactly what happens. Water hits boiling point (100c at sea level) and stays there until all boiled off. So the Sam who takes the longest to cook his egg is the one at the highest altitude; the water reaches a lower max temp so takes longer to cook the egg.
By definition, water is turning into steam once it’s boiling, and thus leaving the pot. So, as they say, the guy who stays close to the ground gets his eggs faster since he gets to cook with hotter water, while the guy who went up gets his eggs slower since he has to cook with colder water.
I’m really tired right now, so I can’t remember the specific vocabulary I need, but I’ll take a quick and dirty stab at this in the knowledge that it’ll be fully explained by others.
Water, like all other substances, needs more energy to change state than it does to just get warmer. Liquid water cannot exist at normal pressure at more than 212 degrees F (or whatever boiling point is at your elevation/pressure). Once a pot of water hits that, it will stay there until it has all turned to steam. That’s one reason why stuff is cooked at boiling, because it’s an easy way to make sure it’s cooking at exactly 212 degrees. So, the higher you are, and the lower the boiling point is, the cooler your water.
MindTrap is a really fun game. I never bothered with the board game rules, but we had a lot of fun with the questions and answers. I wonder where the box got to…
I’m not so sure the question is answered. If we are cooking an egg, does it depend on temperature or does it depend on heat energy? I’m assuming everything is equal here, else we get into some ridiculous situations where it takes forever to hardboil an egg in a bathtub full of water regardless how high or low you are.
My gut says that if you can deliver heat energy at the same rate in both scenarios, the eggs will cook just as quick.
I’ve never played the actual game bot one of my favorite ways to pass the time is to get a group together and read questions back and forth and guess the answers.
Well, yeah, probably, but the point is that the differing altitudes affect how much heat energy boiling water can deliver. Water plateaus at the boiling point, because any H2O that gets hotter than the boiling point turns into steam, which escapes and isn’t useful for heating the egg, assuming we’re talking about a simple pot.
Therefore, if it takes 3 minutes at 100C to boil an egg, then it takes a little longer than 3 minutes to boil an egg at 97C. At higher altitudes, the boiling temp lowers, so higher altitude = longer to cook.
Yep, that’s totally what my wife and I were doing tonight out on the deck. We’re trying to get out of the grind of getting home from work and sitting on asses in front of the tv all the time. Hey, it’s a start.
But your two scenarios are really the same scenario. The temperature at any point inside an egg, at a particular time, depends on the heat flow from the exterior of the egg through the shell to the point of interest. The higher the external temperature, the greater the temperature gradient, and the larger the rate of heat flow.
You can’t, by definition, “deliver heat energy at the same rate” when the temperature differential is different.
On the other side of the equation you have pressure cookers, which work by keeping the water under pressure so it remains liquid at temperatures past 212F, allowing the food to cook much faster.
No, he’s saying an egg requires the same amount of energy in either case. At altitude, because of the lower temperature of the boiling water, it takes a little longer to deliver that same amount of energy.
Turns out someone already covered this whole mess in some detail over here.